Hi, Chris,

Yes, repot ASAP. Your Phalaenopsis is planted in spaghnum moss that has
broken down, and you risk root rot if you let it go longer. Spaghnum moss,
depending on the quality, needs to be replaced at least annually. If the
quality is poor to begin with you might have to repot more frequently. When
you pot it up, trim off any rotten roots and, if you have a good root
structure, trim it a bit to encourage branching.

Look for long strands of spagh with few 'sticks' when you purchase. The
best is from New Zealand, but that appears to be getting harder to find.
Next, IMO, is Chilean. Your best bet is to go to an orchid grower for it,
as they are most likely to have the decent stuff. Soak spaghnum in warm
water (mixed with a fat drop of fertilizer) until uniformly damp. Start
with less water rather than more. You can always add, and you want to avoid
having the stuff soppy. If it does get too wet, wring it out well and then
fluff up before you use it.

watering, remember that the medium may feel dry on top before it begins
to dry out around the roots. Your goal should be moist but not wet or
soppy; you don't want to let spaghnum dry out completely, as it will turn
into a rock! And about light: avoid direct sunlight for Phals.

Good luck!

Diana